Heavy Oil Upgrading Process

ABSTRACT

A process for upgrading heavy oils and bitumen to a crude oil with properties acceptable as a refinery feedstock includes the steps of solvent de-asphalting by separating the polynuclear aromatics including asphaltenes from the heavy oil or bitumen and contacting the de-asphalted oil with biological and chemical reagents to reduce the concentrations of contaminants so as to render the resulting oil an acceptable feedstock for petroleum refineries.

BACKGROUND

Many fossil fuels such as hydrocarbons from oil sand deposits, tar sandsand bitumen, herein referred to as heavy oil, contain polynucleararomatics composed of asphaltenes and resins, heavy metals with nickeland vanadium being the predominant ones and hetero-atoms like oxygen,sulphur and nitrogen in their chemical composition. During refineryoperations, the presence of asphaltenes results in the formation and/orseparation of coke—that plugs the fixed bed of catalysts. The pluggingof a catalyst bed by coke deleteriously leads to the formation of alayer of coke over the catalyst—a phenomenon that prevents the catalystfrom functioning at its efficiency. The nitrogen, sulphur, nickel andvanadium in heavy oils and bitumen also have detrimental effect onrefining operations in that they constitute the poisoning orde-activation agents of the catalyst. Thus the presence of asphaltenes,heavy metals and heteroatoms in heavy oil make the oil an undesirablefeed for many refinery operations—specifically in fixed bed units orfluidized catalytic units and ultimately has a negative effect on thevalue or price of heavy oil.

SUMMARY

We disclose here a process for the upgrading of heavy oil that providesa solution to catalytic poisoning by substantially reducing theconcentrations of contaminants to levels that enable the residualproduct to be used as a desirable feedstock for refineries.

In one embodiment of a heavy oil upgrading process, the concentrationsof contaminants of heavy oils can be reduced substantially by dissolvingthe heavy oil in a de-asphalting hydrocarbon solvent to separate theinsoluble asphaltenes from the soluble oil fraction, and thereaftersubjecting the oil fraction to oxidization, including biological andchemical treatments.

In one embodiment, a heavy oil upgrading process uses a hydrocarbonsolvent composed of a mixture of paraffinic, iso-paraffinic and aromaticsolvents ranging from C₄ to C₁₀ hydrocarbons in the de-asphalting ofheavy oils to produce asphaltenes that are black shiny crystallinesolids that are easily separated from the heavy oil. Examples of theconstituents of the solvent include butane, iso-butane, n-pentane,iso-pentane, n-heptanes, iso-octane and metaxylene with iso-octane beingthe preferred solvent.

For example, in the de-asphalting step the heavy oil may be initiallycontacted with the solvent and heated to a moderate temperature. Themixture is maintained at temperatures in the range of 75° C.-110° C. fora period of 2 to 3 hours. Following the dissolution of the oil over apre-determined time, the asphaltenes are separated from the oil throughgravity or vacuum filtration. Due to the nature of the solvent used inthe de-asphalting phase, the asphaltenes recovered are black, shiny andcrystalline solids that are easily separated from the oil fraction.

In one embodiment of a heavy oil upgrading process, bio-chemicalcatalytic oxidation of nickel, vanadium, sulphur, nitrogen andunsaturated compounds present in high concentrations in heavy oil isconducted in the presence of biological and/or chemical reagents atmoderate temperatures and pressures.

In another embodiment of a heavy oil upgrading process, pressures in therange of 1 atm to 14 atm are applied along with oxidizing reagents andcatalysts to reduce the concentrations of metallic contaminants,unsaturated compounds, and hetero-atoms such as sulphur and nitrogencontained in heavy oil.

In another embodiment of a heavy oil upgrading process, an adsorbentmaterial is used along with the biological and chemical reagents toabsorb the oxidized products from the heavy oil. In one embodiment, aheavy oil upgrading process enhances the API gravity of the heavy oilfrom less than 10 to 30 and above by reducing the concentrations ofcontaminants contained in the oil by a minimum of 50% by weight.

In one embodiment of a heavy oil upgrading process, the de-asphalted oilis contacted with biological reagents that contain enzymes that catalyzethe oxidation of the contaminants in the oil. In one embodiment of aheavy oil upgrading process, biological materials or agricultural wastesare used as reagents to upgrade heavy oil into products that areacceptable as refinery feedstock. The biological oxidation in oneembodiment is accomplished by the introduction of an oxidant and anadsorbent along with the biological reagents into the de-asphalted oiland then subjecting the mixture to temperatures of between 85° C. and150° C. and at pressures ranging from 1 atm to 14 atm for a period oftime, preferably between 2 to 3 hours, and thereafter separating the oilfrom the oxidized contaminants. The oil from this stage is thensubjected to chemical oxidation by the introduction of chemical reagentsincluding adsorbents into the oil and heating the mixture to between105° C. and 180° C. for 1 hour to 3 hours at between 1 atm and 14 atm.Upon completion of the chemical treatment, the oil is separated from theoxidized contaminants through filtration.

In one embodiment of a heavy oil upgrading process, adsorbents are addedto the oil to extract from the biochemically treated oil the polar oroxidized compounds. The separation of the adsorbent and any or allaccompanying oxidized compounds from the oxidized oil may be, forexample, accomplished through gravity or vacuum filtration, orpreferably through a centrifuge or pressure leaf filter. The oilrecovered from the oxidized contaminants is composed of the upgraded oiland the de-asphalting solvent which is ultimately separated from theupgraded oil. The separation of solvent from the upgraded oil may beachieved by various processes such as distillation. The residual oil,following the separation of the solvent, is an upgraded oil which issubstantially reduced in contaminants' concentration and possessescharacteristics that make it acceptable as a refinery feed stock.

In one embodiment, a heavy oil upgrading process provides a bio-chemicalcatalytic process for the oxidation of nickel, vanadium, sulphur,nitrogen and unsaturated compounds by the application of wastebiological reagents in the oxidation of the contaminants and also theapplication of waste iron oxide along with other chemical reagentsincluding a hydrogen donor solvent such as acetic acid.

In one embodiment, a heavy oil upgrading process provides still abio-chemical catalytic oxidation of nickel, vanadium, sulphur, nitrogenand unsaturated compounds contained in heavy oils and bitumen atpressures ranging from 1 atm to 14 atm and at temperatures between 85°C. and 180° C. for 1 hour to 3 hours.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of a heavy oil upgrading process will now be described byway of example with reference to FIG. 1, which is a flow diagram of aheavy oil upgrading process.

DETAILED DESCRIPTION

This detailed description of a heavy oil upgrading process is exemplaryand not intended to limit the scope of the claimed heavy oil upgradingprocess. Immaterial variations from the precise examples set forth hereare intended to be included within the scope of the claims. In theclaims, the word “comprising” is used in its inclusive sense and doesnot exclude other elements being present. The indefinite article “a”before a claim feature does not exclude more than one of the featurebeing present.

Heavy oil from source 10 is transferred to tank 14 where it is mixedwith solvent from tank 12. The mixture is heated (source of heat notshown) for a desired period of time; and upon completion of the reactionbetween the solvent and the heavy oil, the insoluble asphaltenes areseparated through the separation device 16. The asphaltenes arecollected and stored in tank 36 while the de-asphalted oil istransferred to Tank 24. Tank 18 contains biological reagents that areadded to the contents of tank 24 where biological oxidation takes place.The biologically oxidized oil is separated from the oxidizedcontaminants through separator 30 and transferred to reactor 28 leavingthe residue which is stored in tank 38. Chemical reagents from Tank 22are added to the contents of reactor 28 for a chemical oxidation phase.Following the chemical oxidation, the oxidized oil is separated from theoxidation residue through separator 34. The chemical oxidation residueis transferred to storage tank 42 while the oxidized oil is transferredto distillation unit 44 where the initial de-asphalting solvent isseparated from the upgraded oil through atmospheric or vacuumdistillation. The solvent recovered is transferred back into Tank 12while the upgraded oil from unit 44 is collected and stored in Tank 48.

The heavy oil upgrading process described here reduces problemsassociated with high asphaltenes content and high contaminants'concentrations of heavy oil. The heavy oil upgrading process provides aprocess for upgrading heavy oil to crude oils with characteristics thatenable them to be used as refinery feedstock. The heavy oil upgradingprocess provides the dissolution of the heavy oil in a hydrocarbonsolvent comprising of paraffinic, iso-paraffinic and/or aromaticsolvents. This solvent, by virtue of its composition rejects theasphaltenes which separate from the oil as black, shiny, hard andcrystalline solids. Following the separation of asphaltenes from theoil, the heavy oil upgrading process provides the application ofbiological and chemical reagents for the reduction of contaminants'concentration from the de-asphalted oil. An embodiment of the heavy oilupgrading process comprises the steps of solvent de-asphalting followedby bio-chemical treatments as illustrated in FIG. 1. Initially, anamount of the hydrocarbon solvent is added to a specified mass of heavyoil or bitumen to give a solvent to oil ratio where the minimum solventto oil volume ratio is 4:1 and a maximum solvent to oil volume ratio is40:1 with 10:1 being the preferred solvent to oil volume ratio.

The exemplary hydrocarbon solvent herein described is a mixture ofstraight and branch chained paraffinic and aromatic solvents rangingfrom C₄ to C₁₀ examples of which include butane, iso-butane, n-pentane,iso-pentane, n-heptanes iso-octane and metaxylene with iso-octane beingthe preferred solvent. The mixture is heated at atmospheric pressure toa desired temperature and for a time sufficient to cause dissolution ofthe heavy oil in the solvent. The mixture may be heated to a minimumtemperature of 60° C. and a maximum temperature of 120° C., thepreferred temperature being in the range of 105° C.-115° C. underreflux. The residence time may range from one hour to four hours andmost preferably from two to three hours. Under these conditions, theasphaltenes are separated from the oil as insoluble crystalline blackshiny solids and recovered through a proper separation device. Asuitable separation device comprises gravity or vacuum filtration. Theamount of asphaltenes that are typically recovered through this heavyoil upgrading process is approximately 16-20% weight of the heavy oil,although this can vary depending on the source of the heavy oil and alsoon the operating parameters of the de-asphalting process.

Following the de-asphalting phase of the heavy oil upgrading process,biological reagents are introduced to a reactor containing a mass of thede-asphalted oil, the minimum mass of the said de-asphalted oil being 50g and a maximum mass being 2 kg with 750 g as the preferred mass in thisexample. The biological reagents are selected from agricultural wastes,examples of which comprise peat moss, canola hulls, peanut shells,soybean hulls, and cellulose. The biological reagents contain enzymesthat are capable of operating at high temperatures and low pH conditionsand also catalyze the oxidation of the contaminants, particularly nickeland vanadium to their respective oxides at the expense of an oxidizingagent. The addition of the oxidizing agent follows the biologicalreagents. The oxidizing agent may comprise oxides of metals of Group IIAsuch as calcium and magnesium, or oxides of metals of Group VIII such ascobalt, nickel, copper or iron as well as their combinations. Otheroxidizing agents which may be used comprise oxygen, air, ozone, hydrogenperoxide, chlorine, per-acetic acid, formic acid, per-benzoic acid,benzoic acid, and acetic acid. The oxidant, when applied in a liquidform is preferentially added in a range of 0.5% volume to 5.5% volume ofthe heavy oil/bitumen feed, although volume percentages of between 0.1%and 7.2% are also suitable for the process.

A further embodiment of the heavy oil upgrading process is theintroduction of an adsorbent selected from among materials such as:fullers' earth, alumina, zeolite, clay, silica gel, peat moss or acombination of two or more of them into the reaction chamber. Preferredadsorbents are alumina, peat moss, clay or their combinations. In oneembodiment, the adsorbent is applied as a weight percentage of the heavyoil or bitumen from between 0.055% weight and 6.5% weight with thepreferred range being 2.5% weight to 5.5% weight.

The biological oxidation, according to one embodiment of the heavy oilupgrading process, is carried out at pressures ranging from 1 atm to 14atm and at temperatures ranging from 85° C. to 150° C., and over aperiod of time ranging between 2 and 3 hours. Following the biologicaloxidation of the de-asphalted oil, the oxidized oil is separated fromthe contaminants by means of a suitable separation device. Such a devicemay comprise gravity filtration, vacuum filtration, centrifugation, orpressure-leaf filtration.

A further embodiment of the heavy oil upgrading process comprises theintroduction of chemical reagents to the biologically oxidized oil in asecond reactor. The preferred chemical reagents comprise catalysts,examples of which comprise alumina, activated carbon, bituminous coal,lignite char or coconut char. Oxides of Group VIII metals have also beenfound to be useful as oxidation catalysts with the preferred suchcatalyst being iron oxide. As an embodiment of this heavy oil upgradingprocess, iron oxide is derived exclusively from a wastehydrometallurgical metal processing plant. A hydrogen donor solvent,preferably a carboxylic acid solvent may also be employed. Preferredcarboxylic acids may comprise formic or acetic acid. As a furtherembodiment of the heavy oil upgrading process, any one of the oxidantsused in the biological oxidation phase can be used in the chemicaloxidation. As well, the most preferred oxidants comprise iron oxide,water, and hydrogen peroxide or a mixture of aqueous hydrogen peroxideand an acid. As another embodiment of the heavy oil upgrading process,any one of the adsorbents used in the biological oxidation phase can beused in the chemical oxidation.

The mixture of oil, chemical reagents and adsorbent may be heated to asufficient temperature and sufficient pressure over a sufficient amountof time. These parameters comprise a temperature range of 105° C. to180° C., pressures ranging between 1 atm and 14 atm, and times rangingfrom 1 hour to 3 hours. Thereafter, the chemically oxidized oil isseparated from the contaminants via a separation device. Examples ofsuch separation devices comprise gravity filtration, vacuum filtration,centrifugation and pressure filtration.

The oil recovered from the separation unit is further subjected to yetanother separation system to recover the upgraded oil from thede-asphalting solvent. As an embodiment of the heavy oil upgradingprocess, the preferred method of separating the solvent from theupgraded oil is by either atmospheric or vacuum distillation. Thesolvent recovered from the distillation unit is re-used in subsequentde-asphalting phases of the upgrading process. The residual product,following the separation of the solvent is the upgraded oil which issubstantially reduced in contaminants' concentration as disclosed by theresults of the chemical and physical analyses of the product. As anembodiment of the heavy oil upgrading process, the chemical oxidationprocess can precede the biological oxidation.

EXAMPLES OF EXPERIMENTAL WORK Example 1

This example illustrates the effect of using virgin and recycled solventin the de-asphalting phase of the upgrading process.

In a 1 L beaker was accurately weighed 5 g of Alberta heavy oil. 100 mLof virgin solvent was added to the heavy oil to give a 20:1 solvent tooil ratio and the mixture was stirred with heat from a hot plate untilthe formation of an emulsion was observed. With continuous stirring, themixture was heated to a moderate temperature and thereafter, transferredto a 3-neck round bottom 1 L flask provided with a reflux condenser anda thermometer, where the mixture was heated with further stirring for 3hours at a temperatures ranging from 60° C. to 100° C. The mixture wasallowed to cool to ambient temperature and thereafter, the asphalteneswere separated from the de-asphalted oil through filtration, and theweight of dry asphaltenes was recorded. This experiment was repeatedfive times and the average weight of asphaltenes determined. From theaverage weight of asphaltenes, the weight percent of the asphaltenes,based on the initial weight of 5 g of the heavy oil, was calculated. Insimilar experiments, previously used solvent was used in de-asphaltingexperiments as described above. The average weight of asphaltenesrecovered from the five experiments with the recycled solvents wasdetermined and the weight percent of the asphaltenes calculated. Theweight percent of the asphaltenes recovered from the experiments withthe virgin solvent was approximately 18% while the weight percent of theasphaltenes recovered from the experiments with the previously usedsolvent was approximately 13%.

The following examples are based on investigations conducted withsamples of de-asphalted oil derived from composite de-asphalted oilprepared from the reaction between Alberta heavy oil and the solvent.

Example 2

This example illustrates the application of a heavy oil upgradingprocess. Into a 3-neck IL round bottom flask was measured 350 mL sampleof de-asphalted oil. 3 g of biological reagent A and 2 g of biologicalreagent B were added to the de-asphalted oil followed by the addition of1 mL of oxidant. Using a magnetic stirrer, the mixture was subjected tostirring while being heated to 175° C. for 3 hours. During the reactionbetween the oil, the biological reagents, and the oxidant, the enzymesin the agricultural waste or the biological reagents catalyticallyoxidized the contaminants in the oil. This resulted in the formation ofthe oxides of nickel and vanadium. Following the biological oxidation,the oil was separated from the oxidized by-products through filtration.The filtrate was transferred to another 3-neck IL round bottom flask towhich the chemical reagents were added. The chemical reagents includedactivated carbon, iron oxide oxidant, a hydrogen donor solvent, water,and the adsorbent. The mixture was subjected to chemical oxidation byheating it to a temperature range of 120° C.-140° C. for 3 hours and atpressures ranging between 1 atm and 14 atm. Following the chemicaloxidation, the mixture was cooled and filtered. The oxidizedcontaminants from the oil, which included the oxides of the metalsnickel and vanadium, were thus separated from the oil. The post-treatedoil was analyzed for its contaminants concentrations. Table 1 containsthe results of the analyses of the upgraded oil.

TABLE 1 Concentration of contaminants Concentration of in oilConcentration of contaminants in oil treated with oxidant Propertiescontaminants in treated with only and NO of oil the heavy oil as isBiological Reagents Biological Reagents SG @ 1.000 0.8415 0.9088 60/60°F. API 11 37 24 Gravity Ni (ppm) 45 14 21 V (ppm) 128 30 58 S (wt %)6.20 2.62 4.47

Example 3

This example illustrates the effect of using biological reagents ascatalysts in the upgrading process. Into a 3-neck IL round bottom flaskwas measured 500 mL of de-asphalted oil. Specified amounts of the twobiological reagents, A and B were added followed by the addition of anoxidant. Upon heating the mixture for 2 hours at a temperature of 150°C., the mixture was cooled and filtered. The filtrate, which was amixture of the de-asphalting solvent and the biologically upgraded oil,was subjected to a separation process from which the solvent wasrecovered from the upgraded oil. In a comparable experiment, 500 mL ofde-asphalted oil was oxidized under the same experimental conditions asbefore, including the same amount of oxidant, but without any biologicalreagents. Following the separation of the solvent from the upgraded oil,contaminants concentrations of the two upgraded oils were determined.The results are contained in Table 2.

TABLE 2 % Properties Un-treated Upgraded oil Contaminant of Oil HeavyOil by the Process Removed SG @60/60° F. 1.007 0.8475 N/A API Gravity 1135 N/A Ni (ppm) 42 14 69 V (ppm) 128 39 70 S (wt %) 6.20 3.01 52 N (wt%) 0.30 0.11 63

Tables 3 and 4 contain some physical and chemical data of upgraded crudeoils with characteristics of a refinery feedstock produced from thebio-chemical catalytic oxidation process of the present heavy oilupgrading process.

TABLE 3 45/55 59/60 Alberta Heavy Upgraded Upgraded Parameter Method OilCrude Oil Crude Oil Abs Density @ 15° C. ASTM D5002 998 kg/m³ 811.5kg/m³ 828.8 kg/m³ API Gravity @ 15° C. N/A 10 43 39 Relative. Density @15° C. ASTM D5002 1.007 0.8122 0.8295 Total Sulphur ASTM D5453 6.20 Mass% 1.8 Mass % 2.67 Mass % Total Nitrogen ASTM D5291 0.30 Mass % 0.11 Mass% 0.10 Mass % Nickel ASTM D5708A 45 mg/kg 8.5 mg/kg 11 mg/kg VanadiumASTM D5708A 128 mg/kg 27 mg/kg 33 mg/kg MCR ASTM D4530 N/A 2.68 2.72

Table 4 contains a summary by carbon of the fractional composition of acrude oil produced by the bio-chemical catalytic oxidation of Albertaheavy oil.

TABLE 4 C# % Wt % Vol. % Mol C5 0.007 0.008 0.011 C7 4.119 3.518 5.466C8 59.225 61.474 63.902 C9 2.322 2.195 2.274 C10 20.461 19.940 17.740C11 6.827 6.545 5..413 C12 0.588 0.519 0.437

In one embodiment, a heavy oil upgrading process provides further abio-chemical catalytic oxidation process for obtaining, from heavy oilsand bitumen containing 6.20% weight of sulphur and 0.30% weight ofnitrogen as well as 45 ppm of nickel and 128 ppm of vanadium, anupgraded oil containing a minimum of 50% of the original contaminants.

1. A method for removing contaminants from heavy oil, where the heavyoil includes asphaltenes and the contaminants include oxidizablecontaminants, the method comprising: de-asphalting the heavy oil with ahydrocarbon solvent to produce a de-asphalted oil; contacting thede-asphalted oil with a first oxidant in the presence of a first reagentto produce de-asphalted oil containing oxidized contaminants; separatingthe oxidized contaminants from the de-asphalted oil to produce ade-asphalted de-contaminated oil; and separating the hydrocarbon solventfrom the de-asphalted de-contaminated oil to produce upgraded oil. 2.The method of claims 1 in which the hydrocarbon solvent comprisesbutane, iso-butane, n-pentane, iso-pentane, n-heptanes, metaxylene, oriso-octane.
 3. The method of claim 1 in which the de-asphalting stepcomprises: contacting the heavy oil with the hydrocarbon solvent toproduce a mixture of heavy oil and hydrocarbon solvent; while contactingthe heavy oil with the hydrocarbon solvent, heating the mixture of heavyoil and hydrocarbon solvent; and separating the asphaltenes from themixture of heavy oil and hydrocarbon solvent to produce the de-asphaltedoil.
 4. The method of claim 1 in which the first reagent comprises abiological reagent and the oxidized contaminants comprise biologicallyoxidized contaminants, and further comprising contacting thede-asphalted oil with a second oxidant to produce chemically oxidizedcontaminants.
 5. The method of claim 4 in which the biological reagentis obtained from agricultural waste.
 6. The method of claim 4 in whichthe second oxidant is iron oxide.
 7. The method of claim 6 in which theiron oxide is derived from a hydrometallurgical metal processing plantas a waste product.
 8. The method of claim 1 in which contacting thede-asphalted oil with an oxidant takes place in the presence of anadsorbent; the adsorbent comprising of; fuller's earth, alumina,zeolite, silica gel, clay or peat moss.
 9. The method of claim 8 inwhich the adsorbent is added in a concentration comprising between0.055% weight and 6.5% weight of the de-asphalted oil.
 10. The method ofclaim 1 in which the step of contacting the de-asphalted oil with afirst oxidant comprises heating the mixture comprising of de-asphaltedoil, first reagent, and oxidant.
 11. The method of claim 1 in which thefirst oxidant is added in a concentration comprising 0.1% volume and7.2% volume of the de-asphalted oil and more specifically the firstoxidant is added in a concentration between 0.5% volume and 5.5% volumeof the de-asphalted oil.
 12. The method of claim 1 in which the step ofcontacting the de-asphalted oil with a first oxidant is carried out at apressure of between 1 atm and 14 atm.
 13. The method of claim 1 in whichthe first reagent is a biological reagent and in which contacting thede-asphalted oil with the first oxidant is carried out at a temperaturebetween 85° C. and 180° C. for a period of time between 1 hour and 3hours.
 14. The method of claim 1 in which the step of contacting thede-asphalted oil with an oxidant is carried out in the presence of ahydrogen donor solvent comprising at least one of acetic acid and formicacid.
 15. The method of claim 1 in which the step of separating theoxidized contaminants from the de-asphalted oil comprises gravityfiltration, vacuum filtration, centrifugation, or pressure-leaffiltration; and also the step of separating the hydrocarbon solvent fromthe de-asphalted de-contaminated oil comprises using a distillationdevice
 16. A method for bio-chemical catalytic oxidation of contaminantsincluding nickel, vanadium, sulphur and nitrogen as well as unsaturatedcompounds and separating the oxidized by-products from heavy oilcontaminated with the contaminants, comprising: de-asphalting the heavyoil with a solvent comprising paraffinic, iso-paraffinic and aromaticsolvents; contacting the de-asphalted oil with a biological reagentobtained from agricultural waste along with an oxidant and an adsorbentto produce biologically oxidized oil; contacting the biologicallyoxidized oil with a chemical reagent, iron oxide used as an oxidant,acetic acid as a hydrogen donor solvent and an adsorbent to produce adecontaminated oil; and separating the de-asphalting solvent from thedecontaminated oil through distillation.
 17. A method for the removal ofnickel, vanadium, sulphur, nitrogen and unsaturated compounds from heavyoil through bio-chemical catalytic oxidation, comprising: de-asphaltingthe heavy oil to produce a de-asphalted oil; providing pulverizedbiological reagents derived from agricultural wastes of canola hulls,peanut shells and soy bean hulls; providing at least one oxidant;oxidizing the nickel, vanadium and sulphur contaminants by admixing thede-asphalted oil, pulverized biological reagents and oxidant underpressure which ranges from atmospheric pressure to 14 atmospheres and ata temperature between 100° C. to 150° C. under reflux such that thede-asphalted oil, the biological reagents and the oxidant are agitatedfor a time period to obtain a partially biologically oxidizedhydrocarbon stream; and filtering the biologically oxidized oil toseparate the pulverized biological reagents from the partiallybiologically oxidized hydrocarbon stream.
 18. A method for obtaining ahydrocarbon stream suitable for use as a refinery feedstock throughbio-chemical catalytic oxidation of heavy oil contaminated with nickel,vanadium, nitrogen, sulphur and unsaturated compounds, comprising:de-asphalting the heavy oil to produce a de-asphalted oil; treating thede-asphalted oil with an oxidant in the presence of a biologicalreagent; contacting the de-asphalted oil at a pressure above atmosphericpressure and reaction temperature above 60° C. with: pulverized ironoxide as an oxidant derived exclusively from a hydro-metallurgicalprocessing plant as a waste product, at least one organic acid as ahydrogen donor solvent, activated carbon as catalyst derived from one ormore of asphaltenes, coal and coconut shells, water as a catalyst andadsorbent; filtering the de-asphalted oil to separate catalyst, oxidizedcontaminants and adsorbent from hydrocarbons in the de-asphalted oil;and separating the upgraded oil from the de-asphalting solvent.
 19. Themethod of claim 18 further comprising enhancing oxidation by contactingthe de-asphalted oil with activated carbon and organic acid.
 20. Themethod of claim 18 in which the reaction temperature is between 100° C.and 150° C. and maintained for a period of at least 3 hours; and theadsorbent is one or more of zeolites, clay, fuller's earth; and peatmoss.